This application is based on and claims priority to Japanese Patent Application No. 2000-339505, filed Nov. 7, 2000, the entire contents of which is hereby expressly incorporated by reference.
The present invention relates generally to a generator arrangement for an engine, and more particularly to an improved generator cooling arrangement for a watercraft engine.
Watercraft engines typically incorporate electrical generators. The generator rotor is rotated by the engine and the electricity produced is used to recharge the battery or to directly power the ignition system used to ignite the fuel/air mixture inside the cylinder of the engine. Due to the compact design and waterproofing of watercraft engines and the fact that the generator itself produces heat, dissipation of the heat within the generator is an ongoing concern in watercraft applications.
U.S. Pat. No. 6,184,599 assigned to Sanshin Kogyo Kabushiki Kaisha describes improvements in cooling generators including the use of cooling jackets and heat transfer elements.
The preferred embodiments of the present invention, while having a very compact and confined waterproof design, effectively and cost efficiently dissipate the heat created by the generator on an engine in a watercraft.
The stator armature of the generator includes a stack of plates of iron or other material having a high magnetic permeability. The individual plates are insulated from each other by a suitable dielectric. In addition, the stack includes a plate of aluminum that has substantially the same length and width dimensions. The armature coil is then wound around the entire assembly of plural iron plates and the abutting aluminum plate such that the aluminum plate is an integral part of the armature. A generally circular stator mounting bracket is also formed of aluminum. One surface of this bracket directly abuts the engine block. The opposite surface of this bracket directly abuts the aluminum plate integral with the armature stator.
The aluminum plate is thus strategically positioned between the stacked metal plates and the aluminum stator bracket in order to very effectively dissipate heat away from the metal plates of the stator. As a result, the heat produced by resistors heating of the armature coils is directly conducted from the coils and armature iron plates through the integral aluminum plate and the aluminum mounting bracket to the engine block.